/*
 *  FIPS-46-3 compliant Triple-DES implementation
 *
 *  Based on XySSL: Copyright (C) 2006-2008  Christophe Devine
 *
 *  Copyright (C) 2009  Paul Bakker <polarssl_maintainer at polarssl dot org>
 *
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *    * Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *    * Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *    * Neither the names of PolarSSL or XySSL nor the names of its contributors
 *      may be used to endorse or promote products derived from this software
 *      without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 *  TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 *  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/*
 *  DES, on which TDES is based, was originally designed by Horst Feistel
 *  at IBM in 1974, and was adopted as a standard by NIST (formerly NBS).
 *
 *  http://csrc.nist.gov/publications/fips/fips46-3/fips46-3.pdf
 */

#include "netif/ppp/ppp_opts.h"
#if PPP_SUPPORT && LWIP_INCLUDED_POLARSSL_DES

#include "netif/ppp/polarssl/des.h"

/*
 * 32-bit integer manipulation macros (big endian)
 */
#ifndef GET_ULONG_BE
#define GET_ULONG_BE(n, b, i)                                                  \
  {                                                                            \
    (n) = ((unsigned long)(b)[(i)] << 24) |                                    \
          ((unsigned long)(b)[(i) + 1] << 16) |                                \
          ((unsigned long)(b)[(i) + 2] << 8) | ((unsigned long)(b)[(i) + 3]);  \
  }
#endif

#ifndef PUT_ULONG_BE
#define PUT_ULONG_BE(n, b, i)                                                  \
  {                                                                            \
    (b)[(i)] = (unsigned char)((n) >> 24);                                     \
    (b)[(i) + 1] = (unsigned char)((n) >> 16);                                 \
    (b)[(i) + 2] = (unsigned char)((n) >> 8);                                  \
    (b)[(i) + 3] = (unsigned char)((n));                                       \
  }
#endif

/*
 * Expanded DES S-boxes
 */
static const unsigned long SB1[64] = {
    0x01010400, 0x00000000, 0x00010000, 0x01010404, 0x01010004, 0x00010404,
    0x00000004, 0x00010000, 0x00000400, 0x01010400, 0x01010404, 0x00000400,
    0x01000404, 0x01010004, 0x01000000, 0x00000004, 0x00000404, 0x01000400,
    0x01000400, 0x00010400, 0x00010400, 0x01010000, 0x01010000, 0x01000404,
    0x00010004, 0x01000004, 0x01000004, 0x00010004, 0x00000000, 0x00000404,
    0x00010404, 0x01000000, 0x00010000, 0x01010404, 0x00000004, 0x01010000,
    0x01010400, 0x01000000, 0x01000000, 0x00000400, 0x01010004, 0x00010000,
    0x00010400, 0x01000004, 0x00000400, 0x00000004, 0x01000404, 0x00010404,
    0x01010404, 0x00010004, 0x01010000, 0x01000404, 0x01000004, 0x00000404,
    0x00010404, 0x01010400, 0x00000404, 0x01000400, 0x01000400, 0x00000000,
    0x00010004, 0x00010400, 0x00000000, 0x01010004};

static const unsigned long SB2[64] = {
    0x80108020, 0x80008000, 0x00008000, 0x00108020, 0x00100000, 0x00000020,
    0x80100020, 0x80008020, 0x80000020, 0x80108020, 0x80108000, 0x80000000,
    0x80008000, 0x00100000, 0x00000020, 0x80100020, 0x00108000, 0x00100020,
    0x80008020, 0x00000000, 0x80000000, 0x00008000, 0x00108020, 0x80100000,
    0x00100020, 0x80000020, 0x00000000, 0x00108000, 0x00008020, 0x80108000,
    0x80100000, 0x00008020, 0x00000000, 0x00108020, 0x80100020, 0x00100000,
    0x80008020, 0x80100000, 0x80108000, 0x00008000, 0x80100000, 0x80008000,
    0x00000020, 0x80108020, 0x00108020, 0x00000020, 0x00008000, 0x80000000,
    0x00008020, 0x80108000, 0x00100000, 0x80000020, 0x00100020, 0x80008020,
    0x80000020, 0x00100020, 0x00108000, 0x00000000, 0x80008000, 0x00008020,
    0x80000000, 0x80100020, 0x80108020, 0x00108000};

static const unsigned long SB3[64] = {
    0x00000208, 0x08020200, 0x00000000, 0x08020008, 0x08000200, 0x00000000,
    0x00020208, 0x08000200, 0x00020008, 0x08000008, 0x08000008, 0x00020000,
    0x08020208, 0x00020008, 0x08020000, 0x00000208, 0x08000000, 0x00000008,
    0x08020200, 0x00000200, 0x00020200, 0x08020000, 0x08020008, 0x00020208,
    0x08000208, 0x00020200, 0x00020000, 0x08000208, 0x00000008, 0x08020208,
    0x00000200, 0x08000000, 0x08020200, 0x08000000, 0x00020008, 0x00000208,
    0x00020000, 0x08020200, 0x08000200, 0x00000000, 0x00000200, 0x00020008,
    0x08020208, 0x08000200, 0x08000008, 0x00000200, 0x00000000, 0x08020008,
    0x08000208, 0x00020000, 0x08000000, 0x08020208, 0x00000008, 0x00020208,
    0x00020200, 0x08000008, 0x08020000, 0x08000208, 0x00000208, 0x08020000,
    0x00020208, 0x00000008, 0x08020008, 0x00020200};

static const unsigned long SB4[64] = {
    0x00802001, 0x00002081, 0x00002081, 0x00000080, 0x00802080, 0x00800081,
    0x00800001, 0x00002001, 0x00000000, 0x00802000, 0x00802000, 0x00802081,
    0x00000081, 0x00000000, 0x00800080, 0x00800001, 0x00000001, 0x00002000,
    0x00800000, 0x00802001, 0x00000080, 0x00800000, 0x00002001, 0x00002080,
    0x00800081, 0x00000001, 0x00002080, 0x00800080, 0x00002000, 0x00802080,
    0x00802081, 0x00000081, 0x00800080, 0x00800001, 0x00802000, 0x00802081,
    0x00000081, 0x00000000, 0x00000000, 0x00802000, 0x00002080, 0x00800080,
    0x00800081, 0x00000001, 0x00802001, 0x00002081, 0x00002081, 0x00000080,
    0x00802081, 0x00000081, 0x00000001, 0x00002000, 0x00800001, 0x00002001,
    0x00802080, 0x00800081, 0x00002001, 0x00002080, 0x00800000, 0x00802001,
    0x00000080, 0x00800000, 0x00002000, 0x00802080};

static const unsigned long SB5[64] = {
    0x00000100, 0x02080100, 0x02080000, 0x42000100, 0x00080000, 0x00000100,
    0x40000000, 0x02080000, 0x40080100, 0x00080000, 0x02000100, 0x40080100,
    0x42000100, 0x42080000, 0x00080100, 0x40000000, 0x02000000, 0x40080000,
    0x40080000, 0x00000000, 0x40000100, 0x42080100, 0x42080100, 0x02000100,
    0x42080000, 0x40000100, 0x00000000, 0x42000000, 0x02080100, 0x02000000,
    0x42000000, 0x00080100, 0x00080000, 0x42000100, 0x00000100, 0x02000000,
    0x40000000, 0x02080000, 0x42000100, 0x40080100, 0x02000100, 0x40000000,
    0x42080000, 0x02080100, 0x40080100, 0x00000100, 0x02000000, 0x42080000,
    0x42080100, 0x00080100, 0x42000000, 0x42080100, 0x02080000, 0x00000000,
    0x40080000, 0x42000000, 0x00080100, 0x02000100, 0x40000100, 0x00080000,
    0x00000000, 0x40080000, 0x02080100, 0x40000100};

static const unsigned long SB6[64] = {
    0x20000010, 0x20400000, 0x00004000, 0x20404010, 0x20400000, 0x00000010,
    0x20404010, 0x00400000, 0x20004000, 0x00404010, 0x00400000, 0x20000010,
    0x00400010, 0x20004000, 0x20000000, 0x00004010, 0x00000000, 0x00400010,
    0x20004010, 0x00004000, 0x00404000, 0x20004010, 0x00000010, 0x20400010,
    0x20400010, 0x00000000, 0x00404010, 0x20404000, 0x00004010, 0x00404000,
    0x20404000, 0x20000000, 0x20004000, 0x00000010, 0x20400010, 0x00404000,
    0x20404010, 0x00400000, 0x00004010, 0x20000010, 0x00400000, 0x20004000,
    0x20000000, 0x00004010, 0x20000010, 0x20404010, 0x00404000, 0x20400000,
    0x00404010, 0x20404000, 0x00000000, 0x20400010, 0x00000010, 0x00004000,
    0x20400000, 0x00404010, 0x00004000, 0x00400010, 0x20004010, 0x00000000,
    0x20404000, 0x20000000, 0x00400010, 0x20004010};

static const unsigned long SB7[64] = {
    0x00200000, 0x04200002, 0x04000802, 0x00000000, 0x00000800, 0x04000802,
    0x00200802, 0x04200800, 0x04200802, 0x00200000, 0x00000000, 0x04000002,
    0x00000002, 0x04000000, 0x04200002, 0x00000802, 0x04000800, 0x00200802,
    0x00200002, 0x04000800, 0x04000002, 0x04200000, 0x04200800, 0x00200002,
    0x04200000, 0x00000800, 0x00000802, 0x04200802, 0x00200800, 0x00000002,
    0x04000000, 0x00200800, 0x04000000, 0x00200800, 0x00200000, 0x04000802,
    0x04000802, 0x04200002, 0x04200002, 0x00000002, 0x00200002, 0x04000000,
    0x04000800, 0x00200000, 0x04200800, 0x00000802, 0x00200802, 0x04200800,
    0x00000802, 0x04000002, 0x04200802, 0x04200000, 0x00200800, 0x00000000,
    0x00000002, 0x04200802, 0x00000000, 0x00200802, 0x04200000, 0x00000800,
    0x04000002, 0x04000800, 0x00000800, 0x00200002};

static const unsigned long SB8[64] = {
    0x10001040, 0x00001000, 0x00040000, 0x10041040, 0x10000000, 0x10001040,
    0x00000040, 0x10000000, 0x00040040, 0x10040000, 0x10041040, 0x00041000,
    0x10041000, 0x00041040, 0x00001000, 0x00000040, 0x10040000, 0x10000040,
    0x10001000, 0x00001040, 0x00041000, 0x00040040, 0x10040040, 0x10041000,
    0x00001040, 0x00000000, 0x00000000, 0x10040040, 0x10000040, 0x10001000,
    0x00041040, 0x00040000, 0x00041040, 0x00040000, 0x10041000, 0x00001000,
    0x00000040, 0x10040040, 0x00001000, 0x00041040, 0x10001000, 0x00000040,
    0x10000040, 0x10040000, 0x10040040, 0x10000000, 0x00040000, 0x10001040,
    0x00000000, 0x10041040, 0x00040040, 0x10000040, 0x10040000, 0x10001000,
    0x10001040, 0x00000000, 0x10041040, 0x00041000, 0x00041000, 0x00001040,
    0x00001040, 0x00040040, 0x10000000, 0x10041000};

/*
 * PC1: left and right halves bit-swap
 */
static const unsigned long LHs[16] = {
    0x00000000, 0x00000001, 0x00000100, 0x00000101, 0x00010000, 0x00010001,
    0x00010100, 0x00010101, 0x01000000, 0x01000001, 0x01000100, 0x01000101,
    0x01010000, 0x01010001, 0x01010100, 0x01010101};

static const unsigned long RHs[16] = {
    0x00000000, 0x01000000, 0x00010000, 0x01010000, 0x00000100, 0x01000100,
    0x00010100, 0x01010100, 0x00000001, 0x01000001, 0x00010001, 0x01010001,
    0x00000101, 0x01000101, 0x00010101, 0x01010101,
};

/*
 * Initial Permutation macro
 */
#define DES_IP(X, Y)                                                           \
  {                                                                            \
    T = ((X >> 4) ^ Y) & 0x0F0F0F0F;                                           \
    Y ^= T;                                                                    \
    X ^= (T << 4);                                                             \
    T = ((X >> 16) ^ Y) & 0x0000FFFF;                                          \
    Y ^= T;                                                                    \
    X ^= (T << 16);                                                            \
    T = ((Y >> 2) ^ X) & 0x33333333;                                           \
    X ^= T;                                                                    \
    Y ^= (T << 2);                                                             \
    T = ((Y >> 8) ^ X) & 0x00FF00FF;                                           \
    X ^= T;                                                                    \
    Y ^= (T << 8);                                                             \
    Y = ((Y << 1) | (Y >> 31)) & 0xFFFFFFFF;                                   \
    T = (X ^ Y) & 0xAAAAAAAA;                                                  \
    Y ^= T;                                                                    \
    X ^= T;                                                                    \
    X = ((X << 1) | (X >> 31)) & 0xFFFFFFFF;                                   \
  }

/*
 * Final Permutation macro
 */
#define DES_FP(X, Y)                                                           \
  {                                                                            \
    X = ((X << 31) | (X >> 1)) & 0xFFFFFFFF;                                   \
    T = (X ^ Y) & 0xAAAAAAAA;                                                  \
    X ^= T;                                                                    \
    Y ^= T;                                                                    \
    Y = ((Y << 31) | (Y >> 1)) & 0xFFFFFFFF;                                   \
    T = ((Y >> 8) ^ X) & 0x00FF00FF;                                           \
    X ^= T;                                                                    \
    Y ^= (T << 8);                                                             \
    T = ((Y >> 2) ^ X) & 0x33333333;                                           \
    X ^= T;                                                                    \
    Y ^= (T << 2);                                                             \
    T = ((X >> 16) ^ Y) & 0x0000FFFF;                                          \
    Y ^= T;                                                                    \
    X ^= (T << 16);                                                            \
    T = ((X >> 4) ^ Y) & 0x0F0F0F0F;                                           \
    Y ^= T;                                                                    \
    X ^= (T << 4);                                                             \
  }

/*
 * DES round macro
 */
#define DES_ROUND(X, Y)                                                        \
  {                                                                            \
    T = *SK++ ^ X;                                                             \
    Y ^= SB8[(T)&0x3F] ^ SB6[(T >> 8) & 0x3F] ^ SB4[(T >> 16) & 0x3F] ^        \
         SB2[(T >> 24) & 0x3F];                                                \
                                                                               \
    T = *SK++ ^ ((X << 28) | (X >> 4));                                        \
    Y ^= SB7[(T)&0x3F] ^ SB5[(T >> 8) & 0x3F] ^ SB3[(T >> 16) & 0x3F] ^        \
         SB1[(T >> 24) & 0x3F];                                                \
  }

#define SWAP(a, b)                                                             \
  {                                                                            \
    unsigned long t = a;                                                       \
    a = b;                                                                     \
    b = t;                                                                     \
    t = 0;                                                                     \
  }

static void des_setkey(unsigned long SK[32], unsigned char key[8]) {
  int i;
  unsigned long X, Y, T;

  GET_ULONG_BE(X, key, 0);
  GET_ULONG_BE(Y, key, 4);

  /*
   * Permuted Choice 1
   */
  T = ((Y >> 4) ^ X) & 0x0F0F0F0F;
  X ^= T;
  Y ^= (T << 4);
  T = ((Y) ^ X) & 0x10101010;
  X ^= T;
  Y ^= (T);

  X = (LHs[(X)&0xF] << 3) | (LHs[(X >> 8) & 0xF] << 2) |
      (LHs[(X >> 16) & 0xF] << 1) | (LHs[(X >> 24) & 0xF]) |
      (LHs[(X >> 5) & 0xF] << 7) | (LHs[(X >> 13) & 0xF] << 6) |
      (LHs[(X >> 21) & 0xF] << 5) | (LHs[(X >> 29) & 0xF] << 4);

  Y = (RHs[(Y >> 1) & 0xF] << 3) | (RHs[(Y >> 9) & 0xF] << 2) |
      (RHs[(Y >> 17) & 0xF] << 1) | (RHs[(Y >> 25) & 0xF]) |
      (RHs[(Y >> 4) & 0xF] << 7) | (RHs[(Y >> 12) & 0xF] << 6) |
      (RHs[(Y >> 20) & 0xF] << 5) | (RHs[(Y >> 28) & 0xF] << 4);

  X &= 0x0FFFFFFF;
  Y &= 0x0FFFFFFF;

  /*
   * calculate subkeys
   */
  for (i = 0; i < 16; i++) {
    if (i < 2 || i == 8 || i == 15) {
      X = ((X << 1) | (X >> 27)) & 0x0FFFFFFF;
      Y = ((Y << 1) | (Y >> 27)) & 0x0FFFFFFF;
    } else {
      X = ((X << 2) | (X >> 26)) & 0x0FFFFFFF;
      Y = ((Y << 2) | (Y >> 26)) & 0x0FFFFFFF;
    }

    *SK++ = ((X << 4) & 0x24000000) | ((X << 28) & 0x10000000) |
            ((X << 14) & 0x08000000) | ((X << 18) & 0x02080000) |
            ((X << 6) & 0x01000000) | ((X << 9) & 0x00200000) |
            ((X >> 1) & 0x00100000) | ((X << 10) & 0x00040000) |
            ((X << 2) & 0x00020000) | ((X >> 10) & 0x00010000) |
            ((Y >> 13) & 0x00002000) | ((Y >> 4) & 0x00001000) |
            ((Y << 6) & 0x00000800) | ((Y >> 1) & 0x00000400) |
            ((Y >> 14) & 0x00000200) | ((Y)&0x00000100) |
            ((Y >> 5) & 0x00000020) | ((Y >> 10) & 0x00000010) |
            ((Y >> 3) & 0x00000008) | ((Y >> 18) & 0x00000004) |
            ((Y >> 26) & 0x00000002) | ((Y >> 24) & 0x00000001);

    *SK++ = ((X << 15) & 0x20000000) | ((X << 17) & 0x10000000) |
            ((X << 10) & 0x08000000) | ((X << 22) & 0x04000000) |
            ((X >> 2) & 0x02000000) | ((X << 1) & 0x01000000) |
            ((X << 16) & 0x00200000) | ((X << 11) & 0x00100000) |
            ((X << 3) & 0x00080000) | ((X >> 6) & 0x00040000) |
            ((X << 15) & 0x00020000) | ((X >> 4) & 0x00010000) |
            ((Y >> 2) & 0x00002000) | ((Y << 8) & 0x00001000) |
            ((Y >> 14) & 0x00000808) | ((Y >> 9) & 0x00000400) |
            ((Y)&0x00000200) | ((Y << 7) & 0x00000100) |
            ((Y >> 7) & 0x00000020) | ((Y >> 3) & 0x00000011) |
            ((Y << 2) & 0x00000004) | ((Y >> 21) & 0x00000002);
  }
}

/*
 * DES key schedule (56-bit, encryption)
 */
void des_setkey_enc(des_context *ctx, unsigned char key[8]) {
  des_setkey(ctx->sk, key);
}

/*
 * DES key schedule (56-bit, decryption)
 */
void des_setkey_dec(des_context *ctx, unsigned char key[8]) {
  int i;

  des_setkey(ctx->sk, key);

  for (i = 0; i < 16; i += 2) {
    SWAP(ctx->sk[i], ctx->sk[30 - i]);
    SWAP(ctx->sk[i + 1], ctx->sk[31 - i]);
  }
}

/*
 * DES-ECB block encryption/decryption
 */
void des_crypt_ecb(des_context *ctx, const unsigned char input[8],
                   unsigned char output[8]) {
  int i;
  unsigned long X, Y, T, *SK;

  SK = ctx->sk;

  GET_ULONG_BE(X, input, 0);
  GET_ULONG_BE(Y, input, 4);

  DES_IP(X, Y);

  for (i = 0; i < 8; i++) {
    DES_ROUND(Y, X);
    DES_ROUND(X, Y);
  }

  DES_FP(Y, X);

  PUT_ULONG_BE(Y, output, 0);
  PUT_ULONG_BE(X, output, 4);
}

#endif /* PPP_SUPPORT && LWIP_INCLUDED_POLARSSL_DES */
